/**
 * UIScene — HUD overlay on top of GameScene
 *
 * Renders health bar, quick slots, inventory weight.
 * Reads shared game state from Phaser registry.
 */

import Phaser from 'phaser';
import { SLOT_COUNT } from '../player/quickslots';
import { ElementRegistry } from '../chemistry/elements';
import { CompoundRegistry } from '../chemistry/compounds';

const SLOT_SIZE = 44;
const SLOT_GAP = 4;
const HEALTH_BAR_WIDTH = 160;
const HEALTH_BAR_HEIGHT = 14;

/** Get color for a chemical item as number (for rendering) */
function getItemDisplayColor(itemId: string): number {
  const el = ElementRegistry.getBySymbol(itemId);
  if (el) return parseInt(el.color.replace('#', ''), 16);
  const comp = CompoundRegistry.getById(itemId);
  if (comp) return parseInt(comp.color.replace('#', ''), 16);
  return 0xffffff;
}

/** Get display name for a chemical item */
function getItemDisplayName(itemId: string): string {
  const el = ElementRegistry.getBySymbol(itemId);
  if (el) return el.symbol;
  const comp = CompoundRegistry.getById(itemId);
  if (comp) return comp.formula;
  return itemId;
}

export class UIScene extends Phaser.Scene {
  // Health
  private healthBarBg!: Phaser.GameObjects.Rectangle;
  private healthBarFill!: Phaser.GameObjects.Rectangle;
  private healthText!: Phaser.GameObjects.Text;

  // Quick slots
  private slotBoxes: Phaser.GameObjects.Rectangle[] = [];
  private slotTexts: Phaser.GameObjects.Text[] = [];
  private slotNumTexts: Phaser.GameObjects.Text[] = [];
  private slotCountTexts: Phaser.GameObjects.Text[] = [];

  // Inventory
  private invText!: Phaser.GameObjects.Text;

  // Controls hint
  private controlsText!: Phaser.GameObjects.Text;

  // Cycle info (top-left, below health)
  private cycleText!: Phaser.GameObjects.Text;

  // Run phase (top-left, below cycle)
  private phaseText!: Phaser.GameObjects.Text;

  constructor() {
    super({ key: 'UIScene' });
  }

  create(): void {
    const w = this.cameras.main.width;
    const h = this.cameras.main.height;

    // === Health bar (top-left) ===
    const hpX = 12;
    const hpY = 12;

    this.healthBarBg = this.add.rectangle(
      hpX + HEALTH_BAR_WIDTH / 2, hpY + HEALTH_BAR_HEIGHT / 2,
      HEALTH_BAR_WIDTH, HEALTH_BAR_HEIGHT, 0x330000,
    );
    this.healthBarBg.setStrokeStyle(1, 0x660000);

    this.healthBarFill = this.add.rectangle(
      hpX + HEALTH_BAR_WIDTH / 2, hpY + HEALTH_BAR_HEIGHT / 2,
      HEALTH_BAR_WIDTH, HEALTH_BAR_HEIGHT, 0x00cc44,
    );

    this.healthText = this.add.text(
      hpX + HEALTH_BAR_WIDTH + 8, hpY, '', {
        fontSize: '12px',
        color: '#00ff88',
        fontFamily: 'monospace',
      },
    );

    // === Quick slots (bottom-center) ===
    const totalW = SLOT_COUNT * SLOT_SIZE + (SLOT_COUNT - 1) * SLOT_GAP;
    const startX = (w - totalW) / 2;
    const startY = h - SLOT_SIZE - 12;

    for (let i = 0; i < SLOT_COUNT; i++) {
      const x = startX + i * (SLOT_SIZE + SLOT_GAP);
      const cx = x + SLOT_SIZE / 2;
      const cy = startY + SLOT_SIZE / 2;

      // Slot background
      const box = this.add.rectangle(cx, cy, SLOT_SIZE, SLOT_SIZE, 0x111111, 0.85);
      box.setStrokeStyle(2, 0x444444);
      this.slotBoxes.push(box);

      // Slot number (top-left corner)
      const numText = this.add.text(x + 3, startY + 2, `${i + 1}`, {
        fontSize: '10px',
        color: '#555555',
        fontFamily: 'monospace',
      });
      this.slotNumTexts.push(numText);

      // Item name (center)
      const itemText = this.add.text(cx, cy - 2, '', {
        fontSize: '14px',
        color: '#ffffff',
        fontFamily: 'monospace',
        fontStyle: 'bold',
      });
      itemText.setOrigin(0.5);
      this.slotTexts.push(itemText);

      // Count (bottom-right)
      const countText = this.add.text(x + SLOT_SIZE - 3, startY + SLOT_SIZE - 3, '', {
        fontSize: '10px',
        color: '#aaaaaa',
        fontFamily: 'monospace',
      });
      countText.setOrigin(1, 1);
      this.slotCountTexts.push(countText);
    }

    // === Inventory info (bottom-right) ===
    this.invText = this.add.text(w - 12, h - 14, '', {
      fontSize: '11px',
      color: '#888888',
      fontFamily: 'monospace',
      backgroundColor: '#000000aa',
      padding: { x: 4, y: 2 },
    });
    this.invText.setOrigin(1, 1);

    // === Cycle info (top-left, below health bar) ===
    this.cycleText = this.add.text(12, 32, '', {
      fontSize: '10px',
      color: '#446644',
      fontFamily: 'monospace',
    });

    // === Run phase (below cycle) ===
    this.phaseText = this.add.text(12, 46, '', {
      fontSize: '10px',
      color: '#557755',
      fontFamily: 'monospace',
    });

    // === Controls hint (top-right) ===
    this.controlsText = this.add.text(w - 12, 12, 'WASD move | E collect | F throw | 1-4 slots | scroll zoom', {
      fontSize: '10px',
      color: '#444444',
      fontFamily: 'monospace',
    });
    this.controlsText.setOrigin(1, 0);
  }

  update(): void {
    // === Read shared state from registry ===
    const health = (this.registry.get('health') as number) ?? 100;
    const healthMax = (this.registry.get('healthMax') as number) ?? 100;
    const slots = (this.registry.get('quickSlots') as (string | null)[]) ?? [];
    const activeSlot = (this.registry.get('activeSlot') as number) ?? 0;
    const invWeight = (this.registry.get('invWeight') as number) ?? 0;
    const invMaxWeight = (this.registry.get('invMaxWeight') as number) ?? 500;
    const invSlots = (this.registry.get('invSlots') as number) ?? 0;
    const invCounts = (this.registry.get('invCounts') as Map<string, number>) ?? new Map();

    // === Update health bar ===
    const ratio = healthMax > 0 ? health / healthMax : 0;
    const fillWidth = HEALTH_BAR_WIDTH * ratio;
    this.healthBarFill.width = fillWidth;
    this.healthBarFill.x = this.healthBarBg.x - (HEALTH_BAR_WIDTH - fillWidth) / 2;

    // Color: green → yellow → red
    const hpColor = ratio > 0.5 ? 0x00cc44 : ratio > 0.25 ? 0xccaa00 : 0xcc2200;
    this.healthBarFill.setFillStyle(hpColor);
    this.healthText.setText(`${Math.round(health)}/${healthMax}`);

    // === Update quick slots ===
    for (let i = 0; i < SLOT_COUNT; i++) {
      const itemId = i < slots.length ? slots[i] : null;
      const isActive = i === activeSlot;

      // Border color
      this.slotBoxes[i].setStrokeStyle(2, isActive ? 0x00ff88 : 0x444444);
      this.slotBoxes[i].setFillStyle(isActive ? 0x1a2a1a : 0x111111, 0.85);

      if (itemId) {
        const displayName = getItemDisplayName(itemId);
        const displayColor = getItemDisplayColor(itemId);
        this.slotTexts[i].setText(displayName);
        this.slotTexts[i].setColor(`#${displayColor.toString(16).padStart(6, '0')}`);

        const count = invCounts.get(itemId) ?? 0;
        this.slotCountTexts[i].setText(count > 0 ? `${count}` : '0');
        this.slotCountTexts[i].setColor(count > 0 ? '#aaaaaa' : '#660000');
      } else {
        this.slotTexts[i].setText('');
        this.slotCountTexts[i].setText('');
      }
    }

    // === Update inventory ===
    this.invText.setText(`${Math.round(invWeight)}/${invMaxWeight} AMU | ${invSlots} items`);

    // === Update cycle info ===
    const cycleNumber = (this.registry.get('cycleNumber') as number) ?? 1;
    const runInCycle = (this.registry.get('runInCycle') as number) ?? 1;
    const cycleTheme = (this.registry.get('cycleThemeRu') as string) ?? '';
    this.cycleText.setText(`Цикл ${cycleNumber}: ${cycleTheme} | Ран ${runInCycle}/7`);

    // === Update run phase ===
    const runPhaseRu = (this.registry.get('runPhaseRu') as string) ?? '';
    this.phaseText.setText(runPhaseRu);
  }
}